As for Adobe Reader... it's crap. There's many alternatives for Linux that don't take 15 seconds to load.
I showed him KPDF. He downloaded a file that he said he gave up on after 20 minutes (admittedly, on a very old P3 running XP, albeit with a decent cable connection). It DL'd and displayed, in full, in under 5 seconds with KPDF. At that point, he decided he would be willing to put up with headaches on his home computer if it meant he could run linux to take care of the things that windows sucks at.
FWIW though, he also just bought a brand new laptop with Vista and better specs than his AMD single core computer that I built for him for home use. It will be interesting to see how he feels about the two as time goes on..
And for all you people who think I'm not being fair to windows, I'll say upfront, his vista computer has way better specs than the linux machine and I'm 2 hours away, so tech support from me is pretty minimal at this point. He already knows windows XP somewhat well. It will be a very interesting trial... to see how a computer user, using his computer for BUSINESS, sees the two sides of the coin.
My bet is that he'll like both, for different reasons, and will wind up preferring Linux at home and Vista for work. I am betting he will actually save some work specifically to do at home on Linux, but will do less general use surfing/emailing on Vista. Just my hunch..